The surgical closure of a cleft palate is complicated by a lack of mucosa on the palate. After surgery, areas of bare bone remain that heal by secondary intention. This induces the formation of extensive scar tissue attached to the palatal bone. As a result, the growth of the maxilla and the development of the dentition are disturbed. New developments within the field of tissue engineering allow the construction of skin and mucosal substitutes containing cultured cells and artificial matrices. The aim of this study is to develop a substitute for oral mucosa using keratinocytes from the dog. The substitutes are evaluated in a model for cleft palate repair in the dog.